t rex/stage 2+ heads dyno question
t rex/stage 2+ heads dyno question i have GTP stage 2+ heads and a T Rex cam in my 02 SS. through FLP 1 3/4 headers and loud mouth exhaust it made 462/402 to the wheels on a mustang dyno. because of a road hazard that i hit i had to replace the headers, etc. Now i have QTP 1/34 headers which lead to two dynomax bullets dumped. no x pipe,etc. i had my car retuned tonight and i lost 6 hp and 9 tq. i know thats not substantial but now im not even clearning 400 rwtq.
i was told this was due to lack of back pressure, and also due to the heavier springs i just put in the car ( comp 921s...the t rex broke one on the crane duals that were in there) so...456/393 rwhp/tq...are these still good numbers? i see people making 470+ hp and around 420 tq...any suggestions? i am thinking about getting the TSP true duals system if you think that would help
i was told this was due to lack of back pressure, and also due to the heavier springs i just put in the car ( comp 921s...the t rex broke one on the crane duals that were in there) so...456/393 rwhp/tq...are these still good numbers? i see people making 470+ hp and around 420 tq...any suggestions? i am thinking about getting the TSP true duals system if you think that would help
hot weather might be the reason, once we have put ice bags on the intake of a zr1 and saw about 11hp increase 10min break.and i don't think back pressure is the problem, I had a similar cam with hooker headers and y pipe and a cut out in the y pipe , as soon as i open the cut out i see 14hp and about 11 tq .
alright, yea i forgot about that...they did say the weather conditions could have been affecting it too. when i drove the car the other weekend it didn't seem to be a slouch at all. as i said, i ran that 591 hp cobra the other weekend and only got pulled by 3 car lenghts
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From: England
Originally Posted by Cam02ss
i have GTP stage 2+ heads and a T Rex cam in my 02 SS. through FLP 1 3/4 headers and loud mouth exhaust it made 462/402 to the wheels on a mustang dyno. because of a road hazard that i hit i had to replace the headers, etc. Now i have QTP 1/34 headers which lead to two dynomax bullets dumped. no x pipe,etc. i had my car retuned tonight and i lost 6 hp and 9 tq. i know thats not substantial but now im not even clearning 400 rwtq.
i was told this was due to lack of back pressure, and also due to the heavier springs i just put in the car ( comp 921s...the t rex broke one on the crane duals that were in there) so...456/393 rwhp/tq...are these still good numbers? i see people making 470+ hp and around 420 tq...any suggestions? i am thinking about getting the TSP true duals system if you think that would help
i was told this was due to lack of back pressure, and also due to the heavier springs i just put in the car ( comp 921s...the t rex broke one on the crane duals that were in there) so...456/393 rwhp/tq...are these still good numbers? i see people making 470+ hp and around 420 tq...any suggestions? i am thinking about getting the TSP true duals system if you think that would help
Was the same dyno used each time? And where the figures correct to SAE each time? If so then the whether should have had next to no affect on the final reading as that's what SAE corrects do, they correct for atmospheric variances.
Graph smoothing could also be a factor.
Failing that, there's always subtle things like tyres, tyre pressures, bearing, even how square the car is on the dyno.
As direct relation to your setup, well things I could see as possible areas to look are the lack of a mid pipe. A Y pipe scavenges where as having no mid pipe totally negates this ability. You have also affected the exhaust pressure wave.
The heavier springs could certain account for something also.
Backp pressure - nope not at all. Back pressure exists because of flow restriction, your exhaust setup will have less restriction, therefore less backpressure than the LM setup had. As long as the a/f is ok then there should be no problem. However the a/f will probably have altered with the exhaust swap.
Lastly the headers, these could cuase a drop in power. Not due to being better or worse than before. But matching primary length, diameter size with the head port size and flow is important. There is no one ideal header for every car. each setup is different and thus different headers work better on some setups than on others.
I guess a sure fire way to tell is take it to the track and compare trap speeds to those prior.
yes, the same dyno was used each time. As for the SAE..i'll have to check the specifics. The dyno is a mustang 1100 SE if that means anything. True..i didn't think of these numbers compared to if they had been on a dynojet. in the end i guess it doesn't matter what it puts down..the true test is at the track
